Telephone system.



W. A. WYNNE.

TELEPHONE SYSTEM. I APPLICATION FILED MAY 15.1909.

?a.tenbed Dec. 21, 1909.

UNITED STATES. PATENT or a.

WILLIAM A. wYzmn, or ant-awn, NORTH OAROLINA.

' TELEPHONE sysrnm.

To all wiwm it may concern:

Be it known that 1, WILLIAM A. Wynne, a citizen of the United States, residm at Raleigh, in the county of Wake and tate self.

"trolled by the subscriber throng by the cord relays of North Carolina, have invented certain new and useful Improvements in Telephone Systems, of which the following is a specification, reference being had therein to the accompanying drawing.

mvention relates to telephone sfystems, means whereby Without any change in the substationequi pment, a subscriber on a common battery circuit may connect his telephone directly with the answering operators telephone, without the intervention of the ordinary listening key.

I attain my ject by providing in the usual common battery cord circuit branch connections to the operators tele hone conthe cord relay or relays. I preferably employ an aux liary connecting relay controlled jointly and make this auxiliary relay self-locking, carrying the locking circuit therefor through a contact on an operators cut-out key. The'subscriber need only vibrate his hook oncefin order to talk to the operator, and. the operator need only throw over her cut-out key in order to clear her- My invention is illustrated in the accomganying drawing in which the figure is a iagrammatic representatmn of a subscrlbers line and an operators cord circuit including mydistening relay.

R-eferring to the drawing, A is a sub scribers station, provided with the usual common battery equipment, represented as comprising? transmitter T, a receiver R, switch-hoe H, ringer Q, condenser C and induction coil O. This station is connected with a central ofiice marked D, by means of line wires 1--2, terminating at contacts shown as armatures m, m, of a cut-ofl relay M, which normally connect them to the ground, and to the line'relay F, res ectively. On the other side, the relay is connected to the main battery B, and it controls an armature f, to open and close the circuit of the line lamp L in the usual manner. Extensions 3 and 4 of the line wires pass from the cut-01f relay to the sleeve and spring 1' and j of the jack J. As all the subscribers lines may be arranged in the in thecord, and the other r c t of L tt a e Patented Dec. 21,, 1909. 1 Application filed May15, 1909. Serial No. 496,190.

equipment, I have only shown the one,

To interconnect the lines, I provide the cord circuit 5-6, terminating at one endin the answering plug P, and at the other end in the calling plu P. The tip and sleeve contacts p, p o the o erate with the corresponding contacts of t e jack J to connect t e line to the cord. Associated with the calling plug P is a ringing key K, shown asjhaving a pluralit of springs for selective ringing, but whic 1 may be of any desired type, and combined with the listening key if found expedient. The latter key is marked K, and 1n the present case has four pairs of contacts marked in, is, k and k respectively. The first two of these when closed connect the wires and 11 leadin from the operators telephone set 0, to the wires 7 and 8 leading to the cord conductors 5 and 6. The third contact 70 While closed connects the wire 12 to ground at 21, and when the key is used this ground is cut ofi. The wire 12 is the locking wire of the special listening relay W, whose windings are otherwise con nect'ed through wires 15 and'lG to contacts '2; and s of the sleeve and tip relays V and S, of the answerin end of the cord. These two relays contro the answering supervisory lamp main battery during conversation, in the usual manner.

The fourth pair of contacts of the listening key, shown at is, are in the test wire 9, extending from the normally closed back answering plug 00- I contact of the sleeve supervisory relay of the calling end of the cord, to a tertiary windin 2' of the induction coil I of the operators set. The other windings, 2' and 2", of this coil are the usual primary and secondary windings, the first in circuit with the operators transmitter T, and the second with the operators receiver R and the circuit Wires 18-19. These two wires extend from their junction with the wires 1011, to the contacts 'w, w of the listening relay W; and their e06 crating contacts are connected through the wires 13 and 14 respectively to the cord conductors 6 and 5.

The, foregoing description is sufiicient to enable my invention to be understood, the pilot relay G, with its lamp, the condensers parts and connections required for complete operation being i To make a call, the subscriber at A removes ground to B.

through the line circuit 'ing circuit for the relay IV as follows: 13, Gr,

of the usual or any desired type and arrangement.

The operation of this system is as follows:

his receiver from the hook, closing the line circuit and energizing the line relay F over the following path: B, F, m, 2, T, H, Z, m, and ground to B. The lamp L thereupon lights, by reason of the closing of the contacts at 7'. The subscribers operator inserts the answering plug 1 in the jack J, closing circuit of the cut-oti' relay M of the line, and the sleeve relay V of the cord as follows: B (in cord), V, 6, 39 7' 3, M, and M is thereupon energized, pulling up the contacts at and m, disconnecting the wires 1 and 2 from the; ground and the relay I and connecting them to their extensions 3 and 4:. Current then flows and thetip relay S as follows: B (in cord), V, 6, p", y, 3, m, Z, H, T, 2, m, l, j, p, 5, S, and ground 20 to B. Relay V comes up first, simultaneously with M, followed by S. For a briefinterval therefore the circuit of relay \V is closed as follows: B, G, L, o", v, 15, IV, 16, 8, 20 to battery. This interval is very brief however, and cannot be relied upon to permit the energization of relay \V. The subscriber is therefore instructed to first take down his receiver, and then if he wishes quick service, to press down his switclrhook once, with his finger. The plug 1 is supposed to be inserted instantly, but if not, the calling act on the part of the subscriber can be repeated, as this is the natural way to attract the operators attention. After the plug has been inserted, the depression of the hook II by leaving the line open for a moment, deenergizes the relay S, thereby closing the circuit of relay \V already traced. This relay pulls up its armature, and closes contacts at 20,10 and w. w and to connect the wires 18 and 1 1 to the operators circuit 17 and 18,- while the contact w closes a lock- L, 12 0,15, \V, w, 12, is", 21 and ground back to B. The operators set is thus bridged across the cord conductors, and when the subscriber releases the hook, a complete talking circuit is established between his station andthe operator as follows: '1, II, Z, in, ,7 77 7 1 2 5 j, 4, m, 2, T. The relay S immediately pulls up when this circuit is established, but

that the calling subscriber may at times herein,

without effect on the relay W, which remains locked on the wire 12 as long as the listening key K is in its normal or'disused position. The subscriber can give the numcr wanted, or otherwise communicate with the operator, Without delay, and if she Wishes to cut'herself oil, she has only to throw down her key K, thereby opening the contacts is, and depriving the wire 12 of its ground, thus deenergiaing the relay W.

This ope 'ation of the key follows the taking of the number in the ordinary routine, if the switchboard has multiple jacks, for the reason that the operator will then find it necessary to close wire 9 to her tertiary coil 2' for testing.

After a connection is established, the calling subscriber may at any time connect his line direct to the operator in the same manner as before, and each time she will clear herself in like manner. At the conclusion of a conversation, when the calling subscriber hangs up his receiver, the deenergization of relay S will again .bridge' the operators set, producing a click in her ear, and at the same time enabling her to ascertain without any additional act, that the lines are dead and should be disconnected.

This, taken with the supervisoryv lampL cuts down the disconnect time by an estimated. average of one second, or more than twenty-five per cent., giving an increase in eiiiciency of the cord equipment of from three to five per cent. For emergency calls, and for recalls, it gives correspondingly increased etliciency, withthe single drawback succeed in listening in on the operator. This can be prevented however, by keeping all the listening cams of unused cords thrown down, or better still, by making the contacts separate from the listening keys. Even with the arrangement already described, the operator can always out ott the listener by a momentary pressure on the corresponding listening key. If a separate cut-out key is employed it is preferably common to all the cords on one position. 4

It is to be understood while I have shown a specific typeofcommon-battery circuit I am not limited thereto. The gist of the invention lies in the employment of the selflocking relay \V, with means under control of the operator for deenergizing it at will.

Having thus described my invention what I claim and desire to secure by Letters Patcut is 1. In a, telephone system, a plurality of subscribers lines, operators connective link 1 subscribers lines, operators connective link i circuits for interconnecting the lines, an operators telephone set and talking circuit, means associated with a link circuit and adapted to be laced under the control of a calling subscri er,

to enable said subscriber to enable said subscriber telephone set, and a self-locking device con trolled in the actuation of said means.

4. In a telephone system, subscribers lines, an ope 'ators cord circuit for interconnecting said lines, tip and sleeve supervisory relays in said cord circuit, an aux-i ihary relay controlled through the oint ac-l tion of said tip and sleeve relays for connecting the operators ing strands of the cord, and a locking cirruit for said auxiliary relay closed when the same is energized.

'In a telephone system, subscribers lines, an operators cord circuit for interconncrtil'lg said lines. tip and sleeve supervisory relays in said cord circuit, an auxiliary relay controlled through the joint action of said tip and sleeve relays for connecting the operators head-set to the talking strands of the cord, a locking circuit for said auxiliary relay closed when it is energizcd, and means under the control of the operator for breaking said locking circuit.

6. In a telephone system, subscribers lines, an operator's cord circuit for interconnecting said lines, tip and sleeve supervisory relays in said cord circuit, an auxiliary relay controlled through the joint action of said tip and sleeve relays for connecting the operator's head-set to the talk head-set to the talkhaving normally closed contacts in said locking circuit adapted to be opened by the operator to deenergi-ze the relay and disconnect her telephone at will.

7. In a telephone system, a plurality of subscribers lines, an operators link for interconnecting the same, a source of current and a pair of supervisory relays bridged on said link circuit, an auxiliary listening relay joint-ly controlled by said supervisory relays, one of which is adapted to become energized \vhen thetlink is connected with a the subscriber in opening or closing the line circuit at his statlon, a locking circuit for said auxiliary relay, and an operato1"s:listoning key for the locking circuit, together with an operators telephone set and talking ,wires, connected in parallel to contacts of [the auxiliaryvrelay and contacts of th lis- ,tening key respectively, said listenin ;key zlltU'lllg an extra normall closed pair 0 contacts included in the locking circuit; W iereby the energization of one supervisory elay due to connection of the link and the decnergization of the other due to the act of lay to connect, the operators ta king circuit to the talking conductors of the link circuit,

subscriber restores his line -to talking condition,"\a,nd being finally termint ted by deenergization of the auxiliary relay when the operator actuates the listening key.

In testimony whereof I aflix my signature in presence of two vWitnesses. i

t \VILLIAM A. VVYNNE. Witnesses:

Jatms H. Mann, CHARLES LOWELL HOWARD.

ing strands of the cord, a locking circuit for said auxiliary relay, and an operators key 7 line and the other to respond to the act of the, subseribelr, will cause the su ervisory re-;

this connection-being maintained after the 

